Data transformations made easy.
Simply add babel to your list of dependencies in your mix.exs:
def deps do
[
{:babel, "~> 1.0"}
]
endDifferences between the versions are explained in the Changelog.
Documentation gets generated with ExDoc and can be viewed at HexDocs.
Babel was born out of a desire to simplify non-trivial data transformation pipelines.
To focus on the "happy path" instead of having to write a bunch of boilerplate error handling code.
But don't listen to me, take a look for yourself:
pipeline =
Babel.begin()
|> Babel.fetch(["some", "nested", "path"])
|> Babel.map(Babel.into(%{atom_key: Babel.fetch("string-key")}))
data = %{
"some" => %{
"nested" => %{
"path" => [
%{"string-key" => :value2},
%{"string-key" => :value2},
%{"string-key" => :value2}
]
}
}
}
Babel.apply(pipeline, data)
=> {:ok, [
%{atom_key: :value1},
%{atom_key: :value2},
%{atom_key: :value3}
]}Since you'll most likely build non-trivial transformation pipelines with Babel - which can fail at any given step - Babel ships with elaborate error reporting:
pipeline =
Babel.begin()
|> Babel.fetch(["some", "nested", "path"])
|> Babel.map(Babel.into(%{atom_key: Babel.fetch("string-key")}))
data = %{
"some" => %{
"nested" => %{
"path" => [
%{"unexpected-key" => :value1},
%{"unexpected-key" => :value2},
%{"unexpected-key" => :value3}
]
}
}
}
Babel.apply!(pipeline, data)Which will produce the following error:
** (Babel.Error) Failed to transform data: [not_found: "string-key", not_found: "string-key", not_found: "string-key"]
Root Cause(s):
1. Babel.Trace<ERROR>{
data = %{"unexpected-key" => :value1}
Babel.fetch("string-key")
|=> {:error, {:not_found, "string-key"}}
}
2. Babel.Trace<ERROR>{
data = %{"unexpected-key" => :value2}
Babel.fetch("string-key")
|=> {:error, {:not_found, "string-key"}}
}
3. Babel.Trace<ERROR>{
data = %{"unexpected-key" => :value3}
Babel.fetch("string-key")
|=> {:error, {:not_found, "string-key"}}
}
Full Trace:
Babel.Trace<ERROR>{
data = %{"some" => %{"nested" => %{"path" => [%{"unexpected-key" => :value1}, %{"unexpected-key" => :value2}, %{"unexpected-key" => :value3}]}}}
Babel.Pipeline<>
|
| Babel.fetch(["some", "nested", "path"])
| |=< %{"some" => %{"nested" => %{"path" => [%{"unexpected-key" => :value1}, %{...}, ...]}}}
| |=> [%{"unexpected-key" => :value1}, %{"unexpected-key" => :value2}, %{"unexpected-key" => :value3}]
|
| Babel.map(Babel.into(%{atom_key: Babel.fetch("string-key")}))
| |=< [%{"unexpected-key" => :value1}, %{"unexpected-key" => :value2}, %{"unexpected-key" => :value3}]
| |
| | Babel.into(%{atom_key: Babel.fetch("string-key")})
| | |=< %{"unexpected-key" => :value1}
| | |
| | | Babel.fetch("string-key")
| | | |=< %{"unexpected-key" => :value1}
| | | |=> {:error, {:not_found, "string-key"}}
| | |
| | |=> {:error, [not_found: "string-key"]}
| |
| | Babel.into(%{atom_key: Babel.fetch("string-key")})
| | |=< %{"unexpected-key" => :value2}
| | |
| | | Babel.fetch("string-key")
| | | |=< %{"unexpected-key" => :value2}
| | | |=> {:error, {:not_found, "string-key"}}
| | |
| | |=> {:error, [not_found: "string-key"]}
| |
| | Babel.into(%{atom_key: Babel.fetch("string-key")})
| | |=< %{"unexpected-key" => :value3}
| | |
| | | Babel.fetch("string-key")
| | | |=< %{"unexpected-key" => :value3}
| | | |=> {:error, {:not_found, "string-key"}}
| | |
| | |=> {:error, [not_found: "string-key"]}
| |
| |=> {:error, [not_found: "string-key", not_found: "string-key", not_found: "string-key"]}
|
|=> {:error, [not_found: "string-key", not_found: "string-key", not_found: "string-key"]}
}
Babel achieves this by keeping track of all applied steps in a Babel.Trace struct.
Rendering of a Babel.Trace is done through a custom Inspect implementation.
You have to this information everywhere: in the Babel.Error message, in iex, and whenever you inspect a Babel.Error or Babel.Trace.
Contributions are always welcome but please read our contribution guidelines before doing so.